Horizontal Directional Drilling (HDD) is a construction alternative to open trenching for installation of underground utilities, conduit and pipelines. HDD is particularly useful for installing utilities or conduit in areas where open trenching would be impractical due to natural features or existing infrastructure. By using a steerable pilot tool, HDD allows the operator to drill a bore path that avoids existing features in the project area.
Many underground installation projects occur in areas with congested easements or space limitations that require smaller bore paths. When bore paths become smaller due to space considerations and project complexity, the need for responsive and accurate pilot tools increases.
Additionally, HDD projects occur in a variety of ground conditions from hard compacted soils to various loose and solid rock formations. In addition to being responsive and accurate in steering, it is desirable for a pilot tool to be capable of drilling through various ground conditions. Therefore, there is a need for a steerable rock bit that is accurate and responsive and that can drill effectively through hard various soil conditions, including solid rock.